The invention relates to a fuel injection system for mixture-compressing, externally ignited internal combustion engines employing continuous fuel injection into the induction tube. The induction tube includes an air flow rate measuring member and, seriatim, an arbitrarily actuated throttle valve. The air flow rate meter provides the command variable for a follower control loop. The follower control loop includes an electric control amplifier which sets an electromagnetic servomotor that actuates a control slide in a fuel metering valve within the fuel line for the purpose of metering out a fuel quantity in proportion to the air quantity aspirated by the engine.
It is the purpose of fuel injection systems of this type to create automatically a favorable fuel air mixture for all operational conditions of the internal combustion engine, so as to achieve nearly complete fuel combustion and thus to prevent, or at least to reduce sharply, the generation of toxic constituents in the exhaust gas while maintaining the highest possible power or the least fuel consumption of the engine.
In a known fuel injection system of this type, the air flow rate measurement is substantially linear as are the electrical transfer characteristics, resulting in the disadvantage of a low sensitivity of the fuel injection system to changes in the air flow rate in the induction tube during partial load operation of the internal combustion engine.